The present invention relates generally to lighting apparatus, systems, and methods for simultaneously configuring multiple drivers, such as light emitting diode (LED) drivers.
For many luminaire manufacturers it may be desirable to configure the operating parameters of LED drivers before shipping to customers for installation, without requiring coupling of the LED drivers to a mains power source. It is further desirable to configure various operating parameters of the LED driver at other stages of application, again without having to apply mains input power to the LED driver. For example, when a driver is first removed from its packaging, it may be desired to apply a default configuration to satisfy the needs for most of the LED drivers at a particular installation. Further, once a new driver is installed with other LED drivers in a luminaire, it may be required that all the drivers in the luminaire or series of luminaires receive a configuration unique to their installation.
It is also desired to be able to be able to dim an LED driver (or a series of LED drivers) via either an analog signal or a digital data stream. It may also be required that a luminaire or series of luminaires be able to report data regarding its particular operation, such as input or output power.
Generally speaking, conventional dimming control interface circuits are designed for connection to an external device, while a power stage for an associated driver or electronic ballast is designed for connection to a mains AC power source. A conventional interface circuit may be designed to deliver a small current, with a DC control voltage obtained from a variable resistor, shunt regulator, light-level controller, etc. Shunt regulators for example may control electronic ballasts by setting the voltage across the control input terminals to a predetermined voltage range, wherein upon disconnection of the shunt regulator from the control interface the open-circuit voltage across the control terminals rises to approximately the upper end of the range.
In designing for these connections, a lighting device and associated interface circuitry usually include a pair of control signal input terminals for connection to the DC control voltage and a pair of mains AC power input terminals for connection to the external mains power source. However, an all-too common problem during the installation of these lighting devices is where control signal input terminals are inadvertently coupled to a mains line input source. Such an error may result in a great deal of damage to the interface circuitry. Further, where a single interface circuit may be provided for a plurality of drivers, such damage may extend to an array of drivers and multiply the costs of replacement accordingly. Protection circuits are known in the art for protecting the control interface circuitry in electronic ballasts against line voltages. In response to the application of line voltages, high impedance is provided to limit current in the protection circuit and clamping circuitry may be further provided to limit the output voltage from the protection circuit to the interface circuitry and the remainder of the electronic ballast generally. However, such circuits typically also utilize PTC thermistors or high voltage transistors to provide such protection, which increases the cost of the circuit. It would further be desirable to provide a relatively low cost interface circuit with sufficient protection against the application of line voltages.